Is pregnancy loss after amniocentesis related to the volume of amniotic fluid obtained?

The objective was to determine whether pregnancy loss after amniocentesis is related to the amount of amniotic fluid obtained during the procedure.

The study enrolled 2,400 women, all in their sixteenth to twentieth week of pregnancy. A 22G spinal needle was inserted for amniocentesis. The amount of amniotic fluid obtained from 1,200 patients in Group 1 was 4 ml and from 1,200 patients in Group 2 was 20 ml. In Group 1, the amniotic fluid was analyzed with a quantitative fluorescent polymerase chain reaction technique, whereas in Group 2, conventional cytogenetic analysis was used. SPSS 16.0 (chi-square and t tests) was used for statistical analyses.

In Group 1, postamniocentesis premature rupture of membranes (PROM) occurred in four patients (0.3%). There was one unintended fetal loss and postamniocentesis miscarriage rate was 0.08%. In Group 2, postamniocentesis PROM occurred in 12 patients (1%). Eight of these patients experienced fetal loss (0.67%). Fetal loss rates were higher in Group 2 compared with Group 1. These results did not show statistical differences between the groups according to chi-square test (P>0.05).

Although statistical analysis denies the positive effect of obtaining small amounts of amniotic fluid to reduce fetal loss rates in patients after amniocentesis, six to eight times lower fetal loss rates based on the amount of fluid obtained cannot be undervalued.